Which of the following statements can be made concerning the role of the lac repressor (Lac R) in conferring negative control of transcription of the lac operon? (mark all the correct answers)   All of the other answers are correct. Lac R dimers bind to two distant operator sites to form a Lac tetramer, which is facilitated by DNA looping. More than one operator sequence is required for maximal repression by Lac R. Mutations in Lac R that prevent it from binding allolactose result in repression of the lac operon, even in the presence of lactose. A repression loop formed by the binding of LacR to two operator sequences is required for maximal repression by LacR.

Q: 1) The logic of the Lac operon was deciphered by using bacterial lac-operon mutants. Crucial to the…

A: Lac operon is a genetic unit in bacteria that helps in the metabolism of lactose in E.coli and lac…

Q: If an abnormal repressor protein could still bind allolactose but the binding of allolactose did not…

A: The Lac operon contains genes responsible for the transportation and breakdown of lactose. These…

Q: Imagine that you are studying the promoters of genes in E. coli. You notice that genes that are…

A: Lac operon in E.coli. is negatively inducible operon. It has 3 structural genes - LacZ - encodes…

Q: The only way that information is extracted out of DNA is through the transcription of MRNAS that…

A: According to our guideline we can answer only the first question. So upload the second question…

Q: IPTG can be used in the laboratory as a synthetic inducer of the lac operon, instead of lactose.…

A: Lactose operon is an example of inducible operon in which the expression of downstream genes will be…

Q: Which of the following conditions is most likely to result in an increase rate of transcription of…

A: Lactose in bacteria is called beta-galactoside which is used as energy and as a carbon source.…

Q: Consider a mutant of E. coli that has an inactivating mutation in the gene for adenylate cyclase…

A: Inactivating mutations, also known as loss-of-function mutations, cause the gene product to have…

Q: In terms of the efficient use of bacterial resources, explain why it is necessary for lac operon…

A: Lactose can be broken down by E. coli bacteria to produce glucose and galactose. The lac operon…

Q: A bacterial cell is mutated and cannot create the repressor protein associated with the Lac operon.…

A: Lac operon is associated with uptake and metabolism of lactose. It has several components such as a…

Q: The Lac operon is a common example of prokaryotic control of gene expression. In what condition is…

A: Lac operon consists of structural genes such as lacZ, lacY, and lacA which are responsible for the…

Q: If an abnormal repressor protein could still bind allolactose, but thebinding of allolactose did not…

A: Deoxyribonucleic acid is a particle made out of two polynucleotide chains that loop around one…

Q: 5f. Complete the diagrams below to reflect the proteins and any relevant cofactors (e.g. -…

A: The lac operon is an operon, or cluster of genes with one promoter (transcribed as one mRNA). The…

Q: 12) The top operon in E. coli is a group of genes that control the biosynthesis of tryptophan.…

A: Step 1: TRP operon in E. coli is a classical case of gene regulation in prokaryotes' It regulates…

Q: Which of the below conditions would result in the lowest level of expression from the lac operon…

A: Option C is correct :

Q: lacZ isn't expressed, in the presence and absence of glucose and lactose. What components of the lac…

A: If this cell had alternative carbon sources to use for ATP production, like glucose or some other…

Q: An E. coli cell acquires a mutation in the gene that encodes CAP. The mutation affects the…

A: The transcription is a process through which information in the DNA molecule is transcribed into…

Q: Why it is essential to the positive stimulation of transcription of the lac operon ?

A: Lac operon includes the genes that code for the enzymes involved in lactose catabolism.

Q: You have an E.coli strain in which the lac operon is not expressed when glucose is absent and…

A: Introduction :- E. coli is a bacteria that lives in healthy people and animals' intestines. The…

Q: List and describe all the major players involved in transcription of the lac operon in bacteria…

A: Lactose operon is an example of inducible operon and it is the gene expression regulatory mechanism…

Q: Examine the following theoretical operon (gen) in E. coli which contains structural genes (genC,…

A: Question 1:The genB gene's translation would be prematurely stopped by a nonsense mutation in the…

Q: 5f. Complete the diagrams below to reflect the proteins and any relevant cofactors (e.g. -…

A:

Q: Bacteria with a lac phenotype are unable to use lactose because of some defect in expressing the…

A: Answers - 1) False 2) True 3) True  There are 3 structural genes in lac operon - lac Z, lac Y and…

Q: Like the lac operon, the hexose operon is controlled by a separate regulatory protein under the…

A: Hexose operon is the set of structural genes, regulatory genes, promoter and operator sequence in…

Q: You have cells that are mutant in CAP protein such that it cannot bind to CAMP. For these mutant…

A: Cap protein- In solution, the catabolite activator protein (CAP, also known as cAMP receptor…

Q: The symbols A, B, C, D, E represent all the components of the lac operon, excluding LacA. The…

A: The lac operon regulates gene expression in lactose metabolism in E. coli. It is composed of a…

Q: ac operon.  Drag the listed molecules to their corresponding bin. Reset Help   ONPG IPTG X-Gal…

A: ONPG - beta-galactosidase cleaves this molecule to form a visible yellow product. Explaination:  The…

Q: Describe the probable genetic defect that abolishes the sensitivity of the lac operon to the absence…

A: The major carbohydrate source for bacterium are Glucose and Lactose. Glucose is is first choice of…

Q: Suppose you have an E. coli in which the gene that codes for the lac repressor protein has been…

A: Lac operon is an inducible type of operon that involves the breakdown of lactose in E.coli.  The lac…

Q: For the wildtype E. coli two sugars influence the level of transcription of the lactose operon. Fill…

A: Sugars in the growth media cAMP levels (High or Low) Positive regulation occurs (Yes…

Q: Regarding the tryptophan operon in bacteria, in the presence of tryptophan, tryptophan binds to the

A: Q. Regarding the tryptophan operon in bacteria, in the presence of tryptophan, tryptophan binds to…

Q: Consider the following scenario: A bacteria cell is surrounded by lactose, but there is no glucose…

A: Lac operon is an operon model takes place in E coli bacteria . It consists of :- A)Promoter  B )…

Q: For the following types of transcriptional control, indicate whether the protein produced by the…

A: Operon is a functional unit of DNA that consists of cluster of genes under control of promoter. Gene…

Q: How does the repressor protein contribute to selective expression of the structural genes Z, Y, and…

A: The prokaryotic gene expression is regulated by operon system, that regulates the transcription of…

Q: Given the Table below concerning the lac operon, match the letter with what would be occurring for…

A: The lac operon is a genetic system found in bacteria, such as E. coli, that regulates the expression…

Gene Interactions

When the expression of a single trait is influenced by two or more different non-allelic genes, it is termed as genetic interaction. According to Mendel's law of inheritance, each gene functions in its own way and does not depend on the function of another gene, i.e., a single gene controls each of seven characteristics considered, but the complex contribution of many different genes determine many traits of an organism.

Gene Expression

Gene expression is a process by which the instructions present in deoxyribonucleic acid (DNA) are converted into useful molecules such as proteins, and functional messenger ribonucleic (mRNA) molecules in the case of non-protein-coding genes.